<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>empty</title>
<style type="text/css">
div {
	height: 200px;
	background: #abcdef;
}
div:empty {
	background: #f00;
}
</style>
</head>
<body>
<div></div>
<div>Second</div>
<div></div>
<div>Third</div>
</body>
</html>